Warp-Driven Dual-Side Adsorption for Superior Surface-Enhanced Raman Scattering Performance of Transition Metal Dichalcogenides Nanosheets.

Surface-enhanced Raman scattering (SERS) technology is highly sensitive but limited by the high cost of noble-metal substrates and the low enhancement of two-dimensional (2D) materials. This work proposes a dual-sided adsorption strategy utilizing warped structures at the cracks and edges of WSe and MoSe nanosheets grown by Chemical Vapor Deposition (CVD). Driven by capillary forces, probe molecules infiltrate the nanosheet-substrate interface, enabling dual-sided adsorption on both the upper and lower surfaces. This approach enhances SERS signals by up to 20-fold, with a detection limit of 10 M, surpassing most reported traditional single-sided adsorption modes. Additionally, it improves stability by isolating the probe molecules from oxygen. This study further enhanced the formation efficiency and coverage area of the dual-sided adsorption mode by leveraging wide warped structures. It offers new perspectives on the application of crack defects and the potential for the development of high-performance and highly stable SERS substrates.